The present invention relates generally to hoof bath systems for dairy animals, and more particularly to a hoof bath system having in situ chemical mixing, chemical distribution for multiple hoof baths, and improved hoof bath components with improved hoof bath efficiency, efficacy, and automation.
The present invention also relates generally to bovine hoof treatments, and more specifically to bovine hoof treatment compositions and methods having two or more separate components mixed at the dairy to improve efficacy and safety to humans and animals.
Lameness is one of the major problems facing the dairy industry in the world today. The cost of lameness is measured by lost milk production, culled cows, dead cows, additional labor, vet bills, and medicines for treatment. In the U.S. alone, the cost of lameness has been reported to be between $300 and $412 per cow. With an overall estimated incidence rate of 10% to 15%, the annual overall cost of lameness would exceed 570 million dollars. It is especially a problem in large herds, which are the fastest growing segment of the market. The prevalence of lameness in large herds is 50% or more and is reflected by an annual incidence of 60% to 70%. Infectious diseases of the foot or hoof are one of the primary causes of lameness.
Studies have showed that fully a third of all lameness in cows is caused by one disease, digital dermatitis. Digital dermatitis is present worldwide and is estimated to be present in 41% of herds smaller than 100 cows and from 64% to 82% in larger herds. Contagious and debilitating diseases of the bovine foot and hoof include such conditions as bovine hoof rot, digital dermatitis and interdigital dermatitis.
Hoof baths containing germicidal/cleaning chemicals and antibiotics and/or other biologics have been used on dairy operations in the attempt to prevent, control and treat these diseases. Hoof baths are generally located in the return alley of dairy milking barns or parlors. After being milked, the animal will typically walk through the hoof bath on the way back to where they are housed. The feet and hooves will many times contain accumulated dirt and manure, even after milking when at times the feet and hooves are sprayed with water or diluted chemicals. This is especially true in modern dairy facilities with housing contained in limited areas such as free stall or tie stall barns or dry lots instead of open pasture.
In addition, on passing through the hoof bath, the cows may defecate into the hoof bath. The added organic material or load to the hoof bath compromises the antimicrobial products' ability to work in the disinfection and cleansing of the cow feet where the causative microorganisms are located. For economic reasons, the use of antibacterial chemical and biological products in doses high enough to compensate for the organic material present in the hoof bath and to penetrate through organic material and whatever tissue may conceal or otherwise harbor the bacterial pathogens, is usually cost prohibitive. Other chemical products that are less expensive to use at higher doses have the disadvantage in that they may be toxic to the animals, the people working in the dairy facilities or the environment.
Also, many times when one product is used successfully (as in the treatment of digital dermatitis lesions) and the dose or frequency of the dose lessened after successfully eliminating the lesions, the clinical manifestations of the disease will reappear after a short time. One option utilized by many dairy producers is to alternate or rotate more than one chemical or antibiotic product at different times in the same hoof bath. There is at least anecdotal evidence that alternating different chemicals is effective in helping to reduce the incidence and prevalence of infectious diseases of the foot. However, this practice still does not compensate for the above-mentioned problems of using a high enough dose to overcome organic load while still producing a hoof bath that is safe and of low toxicity.
Prior hoof baths were typically recessed into the exit alley and were filled by hand or remotely through a system of pumps, pipes and valves. Dairy operators monitored the baths to determine when fresh chemicals and water needed to be added to the bath. Fresh bath water and chemicals are needed as chemicals lose their efficacy and/or the bath becomes fouled with dirt, debris, and manure.
To clear or flush dirt, debris, and manure from the baths, high pressure and high velocity water was pumped into the bath. Early hoof baths had an upstream end into which flushing water was pumped and a downstream end through which the flushing liquid and flushed materials flowed.
The downstream ends in some hoof bath systems were simple curbs or walls over which the fluid and material is forced by water pressure and/or velocity. Such systems tend to waste water and require unnecessarily high pump pressure. In addition, the inherent nature of a fixed curb can prevent all of the debris from being flushed from the bath.
Drains in the downstream end were added to some such systems to improve flushing performance. Some drains were manually operated, while others were automated to synchronize with flushing and re-filling operations.
In an attempt to further improve flushing performance, at least one system attempted to create specific current flows in the bath during flushing operations by using nozzles of varying jet velocities, sizes, and arrangements. See Vander Veen, U.S. Pat. No. 6,739,286. Such precision is difficult to maintain in actual dairy environments that are subject to harsh conditions, extreme temperature changes, and damage from animals.
As stated above, some hoof bath systems mix chemical and water in the bath. See Vander Veen, U.S. Pat. No. 6,739,286, for example. Such systems can be effective when a single hoof bath is used in a dairy, but using separate chemical and water dispensers in more than one hoof bath unnecessarily complicates piping, pumps, and valves. Duplicate dispensing systems also add expense in building and monitoring such systems. Malfunctions in such duplicative and complicated systems are inevitable.
Accordingly, there is a need for another way to bring safe, efficacious and cost effective doses of these products to the site of the microbial pathogens on the animal without being unduly hindered by organic material that may be present in the bath or on the foot. In addition, there is a need for a system-wide approach for operating hoof baths that reduces initial capital and maintenance expense.